Plastic derivatives of vinylidene chloride



Patented June a 6.. 1 939 John n. Reilly majaupn'm. Wiley, man a,

asaignors to The Dow Chemical Company, Midland, Meli a-corporation memall No Drawing. Application 0mm 12, 193i,

. 1 SerlalNo.168,026

4 6 Claims. 01. m ss) This invention concerns certain plasticized polymeric vinylidene chloride products.- In our co-pendi'ng applications Serial No. 33,126, flied July 25, 1935, of which this application'is a continuation-in-part, and Serial No. 168,200, filed October 9, 1937, we have described the properties of the polymers produced irom monomeric vinylidene chloride having a boiling point at 31.5"-32 C. under 760 millimeters pres-v 10 sure and a specific gravity 0151.22 at'15/ 4 C. when this material is polymerized it yields a product which is only sparingly soluble in boiling tetrachlo'roethane and which is insoluble in. chloroform, carbontetrachloride, ethylene broll mide, and benzene. The polymer issubstantiailyunchanged in composition when heated in a glass container to 180 C. for one hour. The polymer. may be obtained in a variety of physical forms, e. g. gel-like mass, soft porous powder, or hard, 0 bone-like material, depending on the extent. of polymerization. Regardless of the physical form in which it is obtained polymerized pure vinyiidene chloride is resistant to thermal decomposition at temperatures as much as to 30 centig'rade degrees above the softening point of said polymer which is ordinarily between about 170 and 200 C. The polymer is exceptionally resistant to chemical attack by acids, bases, and oxidizing agents. The above described polymeric vinylidene chloride can be molded, extruded, or drawn into desirable shapes only with difllculty at temperatures below its softening point, i. e. about 170 C. or higher. When such a polymer. is heat-treated, its toughness is increased somewhat, but not to modify the plastic properties of such a polymer so as to permit of deformation thereof at moderate temperatures and at readily obtained working pressures. It is also desirable to modify the properties of such a polymer so as to permit'of, a substantial increase in tensile strength and toughness followingheat-tre'ating, operations.

It isaccordingly an object of the present invention to provide. a plastic composition commay be worked at moderate temperatures and v which may be plastically deformed at 'or about room temperatures. It is a further object to v I treated, becomes tough and has s substantially increased tensile strength.

We have now found that the foregoing objects may be readily attained by incorporating in the the extent ordinarily desired. It is desirable to of distilled water for 18 days.

prising polymeric pure vinylidene'chloride which provide such a compositionwhich, when heatagent such as chlorinated diphenyl oxide, chlorinated diphenyl, poly-chloro-benzene, chlorinated naphthalene, and the like, all of which are compatible'with the polymer. Other plasticizers such as butyl phthalate, penta-chloroethane, heza-chloro'ethane, and camphor may be employed but somewhat less advantageously, owing to the fact that they are only slightly compatible with the highly insoluble forms of poly-vinylidene chloride. The plasticizing agent to be employed may be incorporated in the polymer by dis- The plasticizers which we prefer to employ are the chlorinated diphenyl oxides and chlorinated diphenyls, and more particularly such compounds containing from 3 to 6 chlorine atoms per molecule. The lower chlorinated derivatives of diphenyl oxide and diphenyl are for some purposes too volatile to be satisfactorily employed, while those, compounds containing more than about 6, chlorine atoms per molecule tend to crystallize, even when incorporated in the plastic, and do not serve their desired function.

The following examples illustrate the practice of our invention but are not to be construed as limiting the same:

Example 1 800 grams of monomeric vinylidene chloride boiling at 31.8" C., 200 grams of hexa-chl'oro-diphenyl oxide, and 2.5 grams of benzoyl peroxide were polymerized at C. under a half-inch layer The product, a solid cake, was removed, dried in an oven at C. for 3 hours to removea small amount of' water and monomeric vinylidene chloride, and cut 'into bars which were molded in steel dies at C. under pressure of 15,000 pounds per square inthi's fashion gave a tensile. strength of 4,700 pounds per square inch. A duplicate test-bar, after molding, was toughened and heat-treated at C; in glycerine for 3 minutes and remolded in the steel die at 160 C. This bar was stressed to a load of 5,600 pounds per square inch at which load the specimen deformed and pulled through the specimen holder without breaking.

Another bar was molded at '180" C. into a cylindrical specimen, 3. inches long and 0.25 inch in diameter. 'This' specimen showed a tensile inch. A standard A. S..T. M. test bar molded;

strength of 7,500 pounds per square inch and elongation of about 200 per cent.

A non-plasticized test bar of polymeric pure vinylidene chloride, molded at about 180 C. under pressure of approximately 15,000 pounds per square inch, had a tensile strength of approxi-. mately 3,500 pounds per square inch.

Example 2 130 grams of finely powdered poly-vinylidene chloride, prepared by allowing pure monomeric vinylidene chloride to stand exposed to air and ordinary laboratory lighting conditions, was washed on a Buchner filter with several times its volume of acetone and dried for 30 minutes at 60 C. A clear, colorless solution of '70 grams of vtetrachloro-diphenyl oxide in 200 cc. of acetone The incorporation in polymeric vinylidene chloride ofup to 35 per cent by weight of one of the preferred plasticizers has been found to have no material influence upon the inherent solvent resistance of the polymer. To illustrate, a resin containing 35 per cent of hexa-chloro-diphenyl oxide was placed in boiling tetrachloroethane (in which the hexa-chloro-diphenyl oxide is completely soluble) for 3 hours with only a slight swelling of the specimen and a 5 per cent increase in weight. The plasticizer, then, is intimately bound in the polymer and cannot be readily extracted therefrom.

The invention has been illustrated principally with'respect to poly-chloro-diphenyl oxides as plasticizers but other materials of the type hereinbefore enumerated maybe as readily employed with'similar advantageous results. The amount of plasticizer to be incorporated in the polymer may vary through wide limits depending upon the properties desired and upon the compatibility of the plasticizer and the polymer. For

most purposes an amount of plasticizer ranging 1 from 5 to 45 per cent, based on the weight of the be ein-.

We therefore, particularly point out and distinctly claim as our invention:

- 1. A composition comprising polymeric vinylidene chloride prepared from monomeric vinylidene chloride having a boiling point between 315 and 32 0., plasticized with between 5 and about 45 per cent, based on the weight of plasticized composition, of a material selected from the group consisting of chlorinated diphenyl oxides, chlorinated diphenyls, each of the foregoing containing between about 3 and about 6 chlorine atoms per molecule, chloro-naphthalenes, and polychloro-benzenes, to increase the workability of the polymer at low temperatures and to increase toughness and strength thereof when subjected to heat-treatment.

2. A composition comprising polymeric vinylidene chloride prepared from monomeric vinylidene chloride having a boiling point between 31.5 and 32 C., plasticized with between 5 and about -45 per cent, based on the weight of plasticized composition, of chlorinated diphenyl oxide containing between about 3 and about 6 chlorine atoms per molecule, to increase the workability of the polymer at low temperatures and to increase toughness and strength thereof when subjected to heat-treatment. Y I 3. A composition comprising polymeric vinylidene chloride prepared from monomeric vinylidene chloride having a boiling point between 31.5 and 32 C., plasticized with between 5 and about 45 per cent, based on the weight of plasticized composition, of hexachloro-diphenyl oxide, to increase the workability of the polymer at low temperatures and to increase toughness and strengththereof when subjected to heattreatment.

4. The process which comprises dissolving a plasticizer selected from the group consisting of chlorinated diphenyl oxides, chlorinated diphenyls, each of the foregoing containing between about 8 and about 6 chlorine atoms per molecule, poly-chloro-benzenes and chloro-naphthalenes, in monomeric vinylidene chloride having a boiling point between 315 and 32 0., and subject ing the mixture to polymerizing'conditions.

5. The process which comprises dissolving a chlorinated diphenyl oxide containing from 3 to 6 chlorine atoms per molecule in monomeric vinylidene chloride having a boiling point between 31.5 and 32 C., and subjecting the mixture to polymerizing conditions.

6. The process which comprises dissolving hexachloro-diphenyl oxide in monomeric vinylidene chloride having a boiling point between 31.5" and 32? C., and subjecting the mixture to polymerizing conditions.

JOHN H. REILLY. RALPH M. WILEY. 

